Hydroform structural reinforcement system

ABSTRACT

An structural reinforcement system for use with hydroforms and other closed forms having a plurality of members designed to be secured to a closed form, such as an hydroform tube used in automotive applications. A bonding material, such as an epoxy-based reinforcing foam, is disposed on at least a portion of the outer surface of each of the plurality of members. Once the system is attached to the closed form, the foam expands and cures during an automobile assembly operation, bonding the reinforcement system to the hydroform tube and the members. As a result, the reinforcement system provides enhanced load distribution over the vehicle frame without adding excessive weight and further serves to reduce noise and vibrational characteristics of the automotive vehicle.

FIELD OF THE INVENTION

The present invention relates generally to a structural reinforcementsystem for use in increasing the stiffness, strength, or durability ofdifferent portions of automotive or aerospace vehicles. Moreparticularly, the present invention relates to structurally reinforcedclosed forms, such as a hydroform structure or hydroform rail, whichutilizes an expandable and foamable material to cross-link, structurallyadhere, and reinforce the form when the foamable material becomeschemically active and expands upon heating.

BACKGROUND OF THE INVENTION

Traditionally, closed form or hydroforming techniques are used to drawand shape metal tubes. Conventional hydroforming techniques ofteninvolve two steps: (1) placing the desired bends in the tube and (2)forming the tube to the desired configuration. Step 2 of this processusually requires placing a tubular member having an open bore in a moldand pinching off the ends of the tube. A pressurized liquid is theninjected into the open bore, causing the tube to stretch and expand outagainst the mold.

The manufacturing advantages of the hydroforming process is that itallows formation of relatively long tubular structures having a seamlessperimeter. This process eliminates the cost of welding, machining, orfastening operations often used to shape the part in the desiredconfiguration. As a result, a hydroform or closed form structure veryoften has a high length to diameter ratio. For instance, a hydroformstructure may have a length in excess of 15′ and a diameter ranging fromapproximately ¾″ to more than 12″. To this end, a further manufacturingprocess advantage of a hydroform structure is that it can exceed thelength of other tubular members, such as torsion bars or tubular bars,formed using other processes.

Additionally, hydroforming processing creates complex structural shapesthat typically include bends and contour changes. Often the number ofbends and contour changes in a hydroformed bar are greater and morecomplex than those found in torsion bars or other tubular structuresformed using different techniques.

Hydroform structures typically have a constant wall thickness prior toforming, and might develop strength differences at the site of bends orchanges in contour, as well as at certain locations along a long tubularsection. Thus, it is often desirable to reinforce closed form andhydroform sections to improve their structural stiffness, strength, anddurability, particularly in automotive vehicle applications.

Traditional ways of reinforcing tubular structures such as hydroformsand other closed forms include sliding a metal sleeve inside the tubeand welding the reinforcing member in place. However, because thehydroform often includes one or more bends or one or more changes incontour and/or diameter, it is often difficult to insert the sleeve intothe hydroform at the precise location of the weak portion. Othertechniques include reinforcing the hydroform from the outside by weldingthe sleeve onto the outside of the hydroform. However, hydroforms areoften used in applications having very close tolerances, resulting inlittle or no clearance for an externally placed reinforcing member.Accordingly, exterior reinforcements are often not as effective asinterior reinforcements.

Additionally, in many operations the weight of the tubular member iscritical and must be kept low as possible. Thus, the use of an externalsleeve adds unwanted weight to the tubular assembly. Still further, thewelding operation tends to be labor intensive, time consuming andinexact, increasing the cost of forming the hydroform member andproducing parts that have questionable reliability. Finally, theseadditional manufacturing steps and operations are often cumbersome anddifficult to integrate into a final vehicle manufacturing process inthat additional tooling would need to be developed by the manufacturerand assembly plant resources, labor, maintenance, and space would needto be dedicated and expensed by the vehicle manufacturer.

Accordingly, there is a need in industry and manufacturing operationsfor system, device, and method for reinforcing the weak areas of closedforms and other hydroform tubes without significantly increasing theweight and manufacturing complexity. In particular, there is a need forreinforcing a closed form or hydroform, which utilizes a plurality ofmembers or pieces to achieve integrated reinforcement within the closedform since the contour or shape of typical tubes do not allow forplacement of single piece reinforcement members. In this regard, thepresent invention addresses and overcomes the shortcomings found in theprior art by providing a multi-piece reinforcement system having atleast two members capable of being nested together within a hydroformthat may then be fixed in location through the use of a third memberwhich serves as a locking and positioning member of the reinforcementsystem within the hydroform or other closed form. However, design of twonesting member could also create a lock mechanism. Structuralreinforcement of the hydroform is achieved through activation by heat ofan adhesive material disposed along at least two of the members, such amaterial would typically expand to contact a substrate surface and indoing so structurally adhere the multiple members to each other and thehydroform.

SUMMARY OF THE INVENTION

The invention relates to methods and systems for reinforcing a closedform or hydroform member. In one embodiment, the hydroform memberincludes an outer structural member having an open bore; and anexpandable material or structural foam supported by the outer structuralmember. The expandable material extends along at least a portion of thelength of the outer structural member, and may fill at least a portionof the length of the bore.

The expandable material is generally and preferably a heat-activatedepoxy-based resin having foamable characteristics upon activationthrough the use of heat typically encountered in an e-coat or otherautomotive painting operation. As the foam is heated, it expands,cross-links, and structurally adheres to adjacent surfaces. Preferredstructural foam materials are commercially available from L&L Products,Inc. of Romeo, Michigan under the designation L5204, L5206, L5207,L5208, or L5209. Generally speaking, these automotive vehicleapplications may utilize technology and processes such as thosedisclosed in U.S. Pat. Nos. 4,922,596, 4,978,562, 5,124,186, and5,884,960 and commonly owned, co-pending U.S. application Ser. Nos.09/502,686 filed Feb. 11, 2000, 09/524,961 filed Mar. 14, 2000, andparticularly, 09/459,756 filed Dec. 10, 1999, all of which are expresslyincorporated by reference.

The system generally employs two or more members adapted for stiffeningthe structure to be reinforced and helping to redirect applied loads. Inuse, the members are inserted into a closed form, such as a hydroformedtube, with the heat activated bonding material serving as the loadtransferring and potentially energy absorbing medium. In a particularlypreferred embodiment, at least two of the composite members are composedof an injection molded nylon carrier, an injection molded polymer, or amolded metal (such as aluminum, magnesium, and titanium, an alloyderived from the metals or a metallic foam derived from these metals orother metal foam) and it is at least partially coated with a bondingmaterial on at least one of its sides, and in some instances on four ormore sides. A preferred bonding medium is an epoxy-based resin, such asL5204, L5206, L5207, L5208 or L5209 structural foam commerciallyavailable from L & L Products, Inc. of Romeo, Michigan. However, thethird member which serves to lock and position the first two memberscould also utilize an adhesive material along its outer surface. Inaddition, it is contemplated that the member could comprise a nylon orother polymeric material as set forth in commonly owned U.S. Pat. No.6,103,341, expressly incorporated by reference herein. Still further,the member adapted for stiffening the structure to be reinforced couldcomprise a stamped and formed cold-rolled steel, a stamped and formedhigh strength low alloy steel, a stamped and formed transformationinduced plasticity (TRIP) steel, a roll formed cold rolled steel, a rollformed high strength low alloy steel, or a roll formed transformationinduced plasticity (TRIP) steel. In essence, any material that isconsidered structural may be used in conjunction with the structuralfoam. The choice of the structural material used in conjunction with astructural foam or other bonding medium will be dictated by performancerequirements and economics of a specific application.

Additional foamable or expandable materials that could be utilized inthe present invention include other materials which are suitable asbonding or acoustic media and which may be heat activated foams whichgenerally activate and expand to fill a desired cavity or occupy adesired space or function when exposed to temperatures typicallyencountered in automotive e-coat curing ovens and other paint operationsovens. Though other heat-activated materials are possible, a preferredheat activated material is an expandable or flowable polymericformulation, and preferably one that can activate to foam, flow, adhere,or otherwise change states when exposed to the heating operation of atypical automotive assembly painting operation. For example, withoutlimitation, in one embodiment, the polymeric foam is based on ethylenecopolymer or terpolymer that may possess an alpha-olefin. As a copolymeror terpolymer, the polymer is composed of two or three differentmonomers, i.e., small molecules with high chemical reactivity that arecapable of linking up with similar molecules. Examples of particularlypreferred polymers include ethylene vinyl acetate, EPDM, or a mixturethereof Without limitation, other examples of preferred foam formulationthat are commercially available include polymer-based materialcommercially available from L&L Products, Inc. of Romeo, Michigan, underthe designations as L-2105, L-2100, L-7005 or L-2018, L-7101, L7102,L-2411, L-2420, L-4141, etc. and may comprise either open or closed cellpolymeric base material.

Further, it is contemplated that if an acoustic material is used inconjunction with the present invention, when activated through theapplication of heat, it can also assist in the reduction of vibrationand noise in the overall automotive body. In this regard, the nowreinforced closed form or hydroform will have increased stiffness in thecross-members, which will reduce the natural frequency, measured inhertz that resonates through the automotive chassis and reduced acoustictransmission and the ability to block or absorb noise through the use ofthe conjunctive acoustic product. By increasing the stiffness andrigidity of the crossmembers, the noise and frequency of the overallengine ride vibration that occurs from the operation of the vehicle canbe reduced since a reduced frequency of noise and vibration willresonate through the chassis. Although the use of such vibrationreducing materials or media can be utilized instead of, or inconjunction with, the structural expandable material, the preferredembodiment of the structural reinforcement system of the presentinvention utilizes the structurally reinforcing expandable material. Useof acoustic materials in conjunction with structural may provideadditional structural improvement but primarily would be incorporated toimprove NV H characteristics.

It is also contemplated that foamable or expandable material could bedelivered and placed into contact with the member or hydroform, such ashydroform tube found in automotive applications, through a variety ofdelivery systems which include, but are not limited to, a mechanicalsnap fit assembly, extrusion techniques commonly known in the art aswell as a mini-applicator technique as in accordance with the teachingsof commonly owned U.S. Pat. No. 5,358,397 (“Apparatus For ExtrudingFlowable Materials”), hereby expressly incorporated by reference. Inthis non-limiting embodiment, the material or medium is at leastpartially coated with heat-activated polymer that could be structural oracoustic in nature. This preferably heat activated material can besnap-fit onto the chosen surface or substrate; placed into beads orpellets for placement along the chosen substrate or member by means ofextrusion; placed along the substrate through the use of baffletechnology; a die-cutting operation according to teachings that are wellknown in the art; pumpable application systems which could include theuse of a baffle and bladder system; and sprayable applications.

In one embodiment, at least two members composed of an injection moldednylon are provided with a suitable amount of bonding or load transfermedium molded onto its sides in at least one location wherein eachportion is smaller in diameter than a corresponding insertable openingin the form or tube to enable placement within a cavity defined withinan automotive vehicle, such as portions of a hydrofrom tube section orother area or substrate found in an automotive vehicle which couldbenefit from the structural reinforcement characteristics found in thepresent invention. In this embodiment, a first portion corresponds to,and is insertably attached to an opening located within a lower portionof the hydroform tube section. A second portion is slideably engaged andaffixed to an upper surface of the first portion. A third portion isthen utilized to fixedly bridge the first and second portions togetherwithin the hydroform tube. It is contemplated that the bonding mediumcould be applied to a substrate in a variety of patterns, shapes, andthicknesses to accommodate the particular size, shape, and dimensions ofthe cavity corresponding to the chosen form or vehicle application. Theexpandable material or bonding medium is activated to accomplishexpansion through the application of heat typically encountered in anautomotive e-coat oven or other painting operation oven in the spacedefined between the plurality of members and the walls of the hydroformtube defining the cavity. The resulting structure includes the wallstructure of the hydroform tube joined to the plurality of members withthe aid of the structural foam.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and inventive aspects of the present invention will becomemore apparent upon reading the following detailed description, claimsand drawings, of which the following is a brief description:

FIG. 1 is a perspective view of a hydroform structural reinforcementsystem in accordance with the teachings of the present invention.

FIG. 2 is an exploded section view of a portion of a hydroform tubedescribed in FIG. 1, showing the position of the plurality of membersand the expandable material in the uncured state.

FIG. 3 is a cutaway sectional view of a hydroform structuralreinforcement system in accordance with the teachings of the presentinvention showing the plurality of members one of the members comprisingthe hydroform structural reinforcement system of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a reinforced hydroform system 10 formed in accordance withthe teachings of the present invention. The hydroform reinforcementsystem 10 imparts increased strength, stiffness, or durability to astructural member, and, thus, may be used in a variety of applications.For instance, the reinforced hydroform system 10 may be used as part ofthe frame or rail system as for automobiles or building structures.

In a preferred embodiment, as in FIG. 2, the present invention comprisesat least two members 12, 13 composed of an injection molded polymer areprovided with a suitable amount of an expandable material or loadtransfer medium 14, 15 molded on its sides perhaps in a plurality ofportions 16 wherein each portion 16 is smaller in diameter than acorresponding insertable opening in the form or tube 18, o for placementwithin a cavity defined within an automotive vehicle, such as portionsof a hydrofrom tube section or other area or substrate found in anautomotive vehicle which could benefit from the structural reinforcementcharacteristics found in the present invention. In this embodiment, afirst portion 20 corresponds to, and is insertably attached to anopening located within a lower portion of the hydroform tube section. Asecond portion 22 is slideably engaged and affixed to an upper surfaceof the first portion. A third portion 24 is then utilized to fixedlybridge the first 20 and second 22 portions together within the hydroformtube. It is contemplated that the bonding medium 14, 15 could be appliedto a substrate in a variety of patterns, shapes, and thicknesses toaccommodate the particular size, shape, and dimensions of the cavitycorresponding to the chosen form or vehicle application. The expandablematerial or bonding medium 14, 15 is activated to accomplish expansionthrough the application of heat typically encountered in an automotivee-coat oven or other heating operation in the space defined between theplurality of members and the walls of the hydroform tube defining thecavity. The resulting structure includes the wall structure of thehydroform tube joined to the plurality of members with the aid of thestructural foam.

In this preferred embodiment, the first 20 and second 22 portions arenested together within the hydroform tube 18 with each having anapplication of the expandable material or bonding medium 14, 15. Thethird portion 24 is then insertably engaged through the hydroform tube18 as shown in FIG. 2 to serve as a locking and positioning member ofthe reinforcement system within the hydroform or other closed form.Structural reinforcement of the hydroform tube 18 is achieved throughactivation by heat or some other activation stimulus applied to thestructural material 14, 15 disposed along at least first 20 and second22 portions wherein the structural material 14, 15 may expand and willstructurally adhere the first 20, second 22, and third 24 portions toeach other and the hydroform tube 18.

It is contemplated that the structural material or bonding material 14,15 comprises a structural foam, which is preferably heat-activated andexpands and cures upon heating, typically accomplished by gas releasefoaming coupled with a cross-linking chemical reaction. This structuralfoam is generally applied to the members 12, 13 in a solid or semi-solidstate. The structural foam may be applied to the outer surface of themembers 12, 13 in a fluid state using commonly known manufacturingtechniques, wherein the structural foam is heated to a temperature thatpermits the structural foam to flow slightly to aid in substratewetting. Upon curing the structural foam hardens and adheres to theouter surface of the member 12, 13. Alternatively, the structural foammay be applied to the members 12, 13 as precast pellets, which areheated slightly to permit the pellets to bond to the outer surface ofthe members 12, 13. At this stage, the structural foam is heated justenough to cause the structural foam to flow slightly, but not enough tocause the structural foam to thermally expand. Additionally, thestructural foam may also be applied by heat bonding/thermoforming or byco-extrusion. Note that other stimuli activated materials capable ofbonding can be used, such as, without limitation, an encapsulatedmixture of materials that, when activated by temperature, pressure,chemically, or other by other ambient conditions, will become chemicallyactive. To this end, one aspect of the present invention is tofacilitate a streamlined manufacturing process whereby the bondingmaterial 14, 15 can be placed along the members 12, 13 in a desiredconfiguration and inserted within the closed form or hydroform at apoint before final assembly of the vehicle.

The bonding material that may have foamable characteristics is generallyan epoxy-based material, but may include an ethylene copolymer orterpolymer, such as with an alpha-olefin. As a copolymer or terpolymer,the molecule is composed of two or three different monomers, i.e., smallmolecules with high chemical reactivity that are capable of linking upwith similar molecules.

A number of epoxy-based structural reinforcing foams are known in theart and may also be used to produce the bonding material 14 of thepresent invention. A typical structural foam includes a polymeric basematerial, such as an epoxy resin or ethylene-based polymer which, whencompounded with appropriate ingredients (typically a blowing agent andperhaps a curing agent and filler), typically expands and cures in areliable and predictable manner upon the application of heat or anotheractivation stimulus. The resulting material has a low density andsufficient stiffness to impart desired rigidity to a supported article.From a chemical standpoint for a thermally-activated material, thestructural foam is usually initially processed as a thermoplasticmaterial before curing. After curing, the structural foam typicallybecomes a thermoset material that is fixed and incapable of flowing.

An example of a preferred structural foam formulation is an epoxy-basedmaterial that may include polymer modificis such as an ethylenecopolymer or terpolymer that is commercially available from L&LProducts, Inc. of Romeo, Michigan, under the designations L5206, L5207,L5208 and L5209. One advantage of the preferred structural foammaterials over prior art materials is the preferred materials can beprocessed in several ways. Possible processing techniques for thepreferred materials include injection molding, extrusion or extrusionwith a mini-applicator extruder. This enables the creation of partdesigns that exceed the capability of most prior art materials.

While the preferred materials for fabricating the bonding material 14have been disclosed, the material 14 can be formed of other materialsprovided that the material selected is heatactivated or otherwiseactivated by an ambient condition (e.g. moisture, pressure, time or thelike) and expands in a predictable and reliable manner under appropriateconditions for the selected application. One such material is the epoxybased resin disclosed in U.S. Pat. No. application Ser. No. 09/268,810,the teachings of which filed with the United States Patent and TrademarkOffice on Mar. 8, 1999 by the assignee of this application. Some otherpossible materials include, but are not limited to, polyolefinmaterials, copolymers and terpolymers with at least one monomer type analpha-olefin, phenol/formaldehyde materials, phenoxy materials,polyurethane materials with high glass transition temperatures, andmixtures or composites that may include even metallic foams such as analuminum foam composition. See also, U.S. Pat. Nos. 5,766,719;5,755,486; 5,575,526; 5,932,680 (incorporated herein by reference). Ingeneral, the desired characteristics of the structural foam 16 includehigh stiffness, high strength, high glass transition temperature(typically greater than 70 degrees Celsius), and good adhesionretention, particularly in the presence of corrosive or high humidityenvironments.

In applications where a heat activated, thermally expanding material isemployed, an important consideration involved with the selection andformulation of the material comprising the structural foam is thetemperature at which a material reaction or expansion, and possiblycuring, will take place. For instance, in most applications, it isundesirable for the material to be active at room temperature orotherwise at the ambient temperature in a production line environment.More typically, the structural foam becomes reactive at higherprocessing temperatures, such as those encountered in an automobileassembly plant, when the foam is processed along with the automobilecomponents at elevated temperatures or at higher applied energy levels.While temperatures encountered in an automobile assembly body shop ovensmay be in the range of 148.89° C. to 204.44° C. (300° F. to 400° F), andpaint shop oven temps are commonly about 93.33° C. (215° F.) or higher.If needed, blowing agents activators can be incorporated into thecomposition to cause expansion at different temperatures outside theabove ranges.

Generally, prior art expandable acoustic foams have a range of expansionranging from approximately 100 to over 1000 percent. The level ofexpansion of the structural foam 16 may .be increased to as high as 1500percent or more, but is typically between 0% and 300%. In general,higher expansion will produce materials with lower strength andstiffness.

The hydroform reinforcement system 10 disclosed in the present inventionmay be used in a variety of applications where structural reinforcementis desired. The hydroform system 10 has particular application in thoseinstances where the overall weight of the structure being reinforced isa critical factor. For instance, the hydroform system 10 may be used toincrease the structural strength of aircraft frames, marine vehicles,automobile frames, building structures or other similar objects. In theembodiment disclosed the hydroform system 10 is used as part of anautomobile frame to reinforce selected areas of the automobile frame orrails, and may also be utilized in conjunction with rockers,cross-members, chassis engine cradles, radiator/rad supports, and doorimpact bars in automotive vehicles.

As best illustrated in FIGS. 2 and 3, the hydroform reinforcement system10 is suitable for placement within a frame portion of an automobileframe assembly. At least two members 12 composed of an injection moldedpolymer (or other material (e.g., metal) or composite) are provided witha suitable amount of an expandable material or load transfer medium 14molded on its sides in a plurality of portions 16 wherein each portion16 is smaller in diameter than a corresponding insertable opening in theform or tube 18, for placement within a cavity defined within anautomotive vehicle,. such as portions of a hydroform tube section orother area or substrate found in an automotive vehicle which couldbenefit from the structural reinforcement characteristics found in thepresent invention. In this embodiment, a first portion 20 correspondsto, and is insertably attached to an opening located within a lowerportion of the hydroform tube section. A second portion 22 is slideablyengaged and affixed to an upper surface of the first portion. A thirdportion 24 is then utilized to fixedly bridge the first 20 and second 22portions together within the hydroform tube. It will be appreciated thatthe hydroform reinforcement system 10 of the present invention may beused to reinforce other areas of an automobile frame or rocker assemblyand the number of members 12 and placement of the expandable material 14along the members 12 would be dictated by the shape and desiredapplication.

Though other heat activated materials are possible, a preferred heatactivated material is an expandable polymeric material, and preferablyone that is foamable. A particularly preferred material is anepoxy-based structural foam. For example, without limitation, in oneembodiment, the structural foam is an epoxy-based material that mayinclude an ethylene copolymer or terpolymer.

A number of epoxy-based structural reinforcing foams are known in theart and may also be used to produce the structural foam. A typicalstructural foam includes a polymeric base material, such as an epoxyresin or ethylene-based polymer which, when compounded with appropriateingredients (typically a blowing and curing agent), expands and cures ina reliable and predicable manner upon the application of heat or theoccurrence of a particular ambient condition. From a chemical standpointfor a thermally-activated material, the structural foam is usuallyinitially processed as a flowable thermoplastic material before curing.It will cross-link upon curing, which makes the material incapable offurther flow.

Some other possible materials include, but are not limited to,polyolefin materials, copolymers and terpolymers with at least onemonomer type an alpha-olefin, phenol/formaldehyde materials, phenoxymaterials, and polyurethane. See also, U.S. Pat. Nos. 5,266,133;5,766,719; 5,755,486; 5,575,526; 5,932,680; and WO 00/27920 (PCTIUS99/24795) (all of which are expressly incorporated by reference). Ingeneral, the desired characteristics of the resulting material includerelatively high glass transition point, and good environmentaldegradation resistance properties. In this manner, the material does notgenerally interfere with the materials systems employed by automobilemanufacturers. Moreover, it will withstand the processing conditionstypically encountered in the manufacture of a vehicle, such as thee-coat priming, cleaning and degreasing and other coating processes, aswell as the painting operations encountered in final vehicle assembly.

In another embodiment, the material 14 is provided in an encapsulated orpartially encapsulated form, which may comprise a pellet, which includesan expandable foamable material, encapsulated or partially encapsulatedin an adhesive shell, which could then be attached to the members 12 ina desired configuration. An example of one such system is disclosed incommonly owned, co-pending U.S. application Ser. No. 09/524,298(“Expandable Pre-Formed Plug”), hereby incorporated by reference. Inaddition, as discussed previously, preformed patterns may also beemployed such as those made by extruding a sheet (having a flat orcontoured surface) and then die cutting it according to a predeterminedconfiguration.

The skilled artisan will appreciate that the system may be employed incombination with or as a component of a conventional sound blockingbaffle, or a vehicle structural reinforcement system, such as isdisclosed in commonly owned co-pending U.S. application Ser. Nos.09/524,961 or 09/502,686 (hereby incorporated by reference).

A number of advantages are realized in accordance with the presentinvention, including, but not limited to, the ability to manufacture astructural reinforcement system for use in a hydroform or other closedform for delivery and assembly at a vehicle assembly plant without theneed for application of pumpable products, wet chemical products, andmultiple sets of tools, such as for other prior art.

The preferred embodiment of the present invention has been disclosed. Aperson of ordinary skill in the art would realize however, that certainmodifications would come within the teachings of this invention.Therefore, the following claims should be studied to determine the truescope and content of the invention.

What is claimed is:
 1. A system made of portions for use in reinforcinga hydroformed tube of an automotive vehicle, the system comprising: (a)a first portion that includes a first member and an expandable materialmolded upon the first member, the first portion also including an uppersurface and the first portion being configured for insertion into thehydroformed tube; (b) a second portion that includes a second member andan expandable material molded upon the second member, the second portionconfigured to be affixed to the upper surface of the first portion whilein the hydroformed tube; and (c) a third portion configured to beinserted through the hydroformed tube to lock and position the firstportion and said second portion together to form the system while in thehydroformed tube; wherein the first portion is placed within thehydroformed tube followed by placement of the second portion within thehydroformed tube; and wherein the expandable material of the firstportion and second portion expands to fixedly position the system withinthe hydroformed tube.
 2. The system as claimed in claim 1, wherein thefirst member and the second member are comprised of a stamped and formedcold rolled steel.
 3. The system as claimed in claim 1, wherein thefirst member and the second member are comprised of a stamped and formedhigh strength low alloy steel.
 4. The system as claimed in claim 1,wherein the first member and the second member are comprised of astamped and formed transformation induced plasticity steel.
 5. Thesystem as claimed in claim 1, wherein the first member and the secondmember are comprised of a roll formed cold rolled steel.
 6. The systemas claimed in claim 1, wherein the first member and the second memberare comprised of a roll formed high strength low alloy steel.
 7. Thesystem as claimed in claim 1, wherein the first member and the secondmember are comprised of a roll formed transformation induced plasticitysteel.
 8. The system as claimed in claim 1, wherein the first member andthe second member are comprised of a molded plastic.
 9. The system asclaimed in claim 1, wherein the expandable material of the first portionand the second portion is a polymeric material.
 10. The system asclaimed in claim 1, wherein the expandable material of the first portionand the second portion is a polymeric material having foamablecharacteristics.
 11. The system as claimed in claim 1, wherein theexpandable material of the first portion and the second portion is anepoxy-based polymer having foamable characteristics.
 12. The system asclaimed in claim 1, wherein the expandable material of the first portionand the second portion is a heat activated expandable polymer foam. 13.The system as claimed in claim 1, wherein the expandable material of thefirst portion and the second portion is an expandable foam that isgenerally free of tack to the touch.
 14. The system as claimed in claim1, wherein the expandable material of the first portion and the secondportion is an expandable polymeric material having foamablecharacteristics that can be activated at a temperature encountered in anautomotive vehicle paint operation ovens.